The presence of corrosive products, oil insoluble contaminants or ferromagnetic particles in a lubricating oil can create a threat to the system in which the oil is used because of the unnecessary wear and damage that can occur to the system if the oil is not promptly changed.
Many methods and devices have been developed to detect the contamination or breakdown of oil. One such device, shown in U.S. Pat. No. 4,646,070 issued to Yasuhara, discloses a device for detecting deterioration in lubricating oil which comprises a pair of capacitor electrodes positioned in the lubricating oil. The device uses the oil as a dielectric between the sensors to develop a frequency voltage signal across the sensor capacitor, thus determining the dielectric and deterioration of the oil. A major drawback of this device and others is that they do not inform the tester of the specific type or magnitude of deterioration in the system.
The preferred embodiment of the present invention allows simultaneous testing and identification of corrosive products, contamination, and ferromagnetic wear particles. Thus, since the apparatus detects the type of products present in the oil, a user is able to make a more knowledgeable determination of the conditions causing the deterioration of the oil. Furthermore, the device provides this determination much more economically than laboratory testing. The device also allows multiple tests of the same oil sample because it does not consume the sample during the testing process. Preferably, the device allows testing of the oil outside the system in which the oil is used, thereby allowing the oils of many different systems to be tested by the same device.